1. Field of the Invention
This invention generally relates to battery powered vehicles, and, more specifically, relates to an apparatus and method for replacing a large battery pack in a battery powered vehicle.
2. Description of the Related Art
Battery packs for battery powered vehicles are very large and heavy, typically weighing 1500 lbs or more. The prior art systems for replacing these battery packs use a chainfall or block and tackle hoist arrangement. The hoist is connected to the discharged battery pack within the vehicle, the battery pack is lifted out of the vehicle, and the hoist is moved to a position to off load the discharged battery pack. The hoist is then moved to a position where a fresh battery pack is stored, the hoist is connected to this fresh battery pack, the fresh battery pack is lifted by the hoist, the hoist is moved to the waiting vehicle, and the battery pack is lowered into place. This operation is time-consuming and requires a great deal of skill and effort of the operator changing the battery packs.
An alternative system of the prior art has been used which uses a hoist in conjunction with a roll off dolly. A roll off dolly has wheels at the base for easy rolling, and has one or more belts or rollers on the top platform to allow an item to be easily moved to and from the dolly. The discharged battery pack in the vehicle is slid out of the vehicle onto the top platform of the roll off dolly. The dolly is then wheeled to the off load area, and the battery pack is lifted with a hoist off the roll off dolly and placed in a location for charging. A hoist is then used to lift a fresh battery pack and place it on top of the roll off dolly. The dolly is then wheeled to the vehicle, and the battery pack is then slid from the dolly into the vehicle.
The use of either of these prior art systems for loading and unloading a battery pack into and out of a battery powered vehicle is time-consuming, and requires a great deal of assistance and effort from the operator.
Therefore, there existed a need to provide an apparatus and method for quickly removing a used battery pack from a battery operated vehicle, and for installing a fresh battery pack into the vehicle in a very short time period, and with little effort by the operator.